Known loading devices for packaging machines for the purposes described can be provided with a filling shoe for feeding small articles into a plurality of receptacles, preferably molded receptacles, of a package component moving below the filling shoe and past it.
Examples of this package component include a molded foil or a molded plate with a slidable partition positioned between the molded plate and a molded foil having molded receptacles therein, wherein the filling shoe has at least one feed chamber, which has a mouth open to the package component and its receptacles and into which a product duct empties feeding the product items in series one after another.
In the loading apparatus of this type in the prior art, the force of gravity is not sufficient to slide the articles quickly enough through the product duct into the feed chamber so that it falls out of the feed chamber into a preferably molded receptacle. It is known to speed up the product feed by a pressurized air flow, which is provided through an air passage connected just in front of the end of the feed chamber, so that the air flow acts only on the product found directly in front of the feed chamber.
The material therefore blown into the feed chamber reaches one of the receptacles into which it drops as before by free fall, because on the latter part of its trajectory acceleration by the pressurized air flow is absent. The air escapes from the feed chamber substantially through the gap between the filling shoe and the package component and, if necessary, also through an air escape passage connected to the feed chamber.
With the increasing speed of the package component feed, the filling speed of the product must also increase and therefore the speed of the air flow must also be elevated. That however has the disadvantage that a strong air vortex arises in the receptacles, which produces a back pressure and hinders the fall of the product from the feed chamber into the receptacles. The product which does not quickly enough reach the preferably molded receptacle can hang between the edges of the feed chamber and the preferably molded receptacle and as a result of the package component motion be damaged.
With a correspondingly higher air flow the damming-up effect of the air vortex is so strong that the product no longer reaches the bottom of one of the receptacles, but hangs in or over the receptacle and under certain circumstances is blow from the receptacle. Because of that the filling speed has an upper limit with this system.
A further disadvantage of the above-described pressurized air flow method for product feed and load assistance is that dust build up is not prevented. The dust carried along by the air flow into the outlet from the feed chamber pollutes the sealing surfaces of the packaging foil. Still more serious however is the fact that the dust carried by the pressurized air to the outside into the environment originates as a rule from the product and also can originate from its filling, when for example the capsules are damaged. Often it is a matter of a highly biologically active material such as sleeping pills, hormonal stimulants and materials, poisons or the like, by which the surroundings and persons functioning therein can be heavily dosed and correspondingly affected.
Further disadvantages of the pressurized air flow method are seen in the increased consumption of materials and a correspondingly increased cost as well as an annoying, disturbing air flow noise. Besides the pressurized air flow from the pressurized air source contaminates and renders nonsterile everything it contacts.